check在oracle
CREATE TABLE orders ( order_id NUMBER(10), order_price NUMBER(10, 2) CHECK (order_price >0 AND order_price
除了限制数字范围,check约束还可以用于限制字符串的长度或格式。例如,如果我们想确保电话号码的格式必须为xxx-xxxx-xxxx,我们可以使用如下的check约束定义:
CREATE TABLE customers ( customer_id NUMBER(10), customer_name VARCHAR2(50), customer_phone VARCHAR2(20) CHECK (REGEXP_LIKE(customer_phone, '\d{3}-\d{4}-\d{4}')) );